This application is related to U.S. application Ser. No. 447,815, now U.S. Pat. No. b 4,579,054, of D. P. Baun et al., for "Stand-Alone Electronic Mailing Machine", and to U.S. application Ser. No. 447,913, now abandoned, of A. B. Eckert, Jr. et. al., for "Initializing The Print Wheels In An Electronic Postage Meter"; both of which applications were filed concurrently herewith, are assigned to the assignee of the present invention and are hereby specifically incorporated herein by reference. In addition, this application is related to five additional concurrently filed co-pending patent applications, each of which is assigned to the assignee of the present invention, i.e., U.S. patent application Ser. No. 447,861, now U.S. Pat. No. 4,577,283, for Postage meter with keyboard keys for causing meter operations to be performed: Ser. No. 447,901, for Postage meter with keyboard keys for commanding and requesting performance of meter operations; Ser. No. 447,905, now U.S. Pat. No. 4,509,141, for Postage meter with keyboard keys used for changing operating constants; Ser. No. 447,870, now U.S. Pat. No. 4,535,407, for Postage meter with keyboard keys used for changing postage unused amount; and Ser. No. 447,919, for Postage meter with keyboard keys for causing display of data pertaining to meter operations.
Currently available electronic postal meters of, for example, the type disclosed in U.S. Pat. No. 4,301,507 for an Electronic Postage Meter Having Plural Computing Systems, issued Nov. 17, 1981 to J. H. Soderberg et al., and assigned to the assignee of the present invention, are generally provided with a keyboard for entering numerical postal values that are to be printed, a display for visually indicating the entered postage and other values, a printing mechanism and a micro-computer including accounting means and means for controlling the various functions of the postal meter.
In the aforesaid U.S. Pat. No. 4,301,507 the various components of the postal meter are compartmented according to their functions to form three units, referred to as the control, accounting and printing units. Each of the units incorporates a dedicated microprocessor having a separately controlled clock and programs. And, two-way communications are conducted via serial channels between the units, and via serial channels between the postage meter and any external apparatus connected to the meter, in the form of serially transmitted single byte "header" only messages, consisting of ten bits including a start bit followed by an 8 bit byte which is in turn followed by a stop bit, or in the form of a multi-byte message consisting of a header and one or more additional bytes of information. All transmitted messages are followed by a no error pulse if the echoplex message was received error free. In practice, each of the units is capable of processing data independently and asynchronously of the other. Further, to allow for compatibility between the postal meter and any external apparatus, all operational data transmitted to, from and between each of the three units and all stored operator information is accessible via the postal meter interface, as a result of which the external apparatus (if any) may be adapted to have complete control of the postal meter as well as access to all current operational information in the postal meter. In addition, the flow of messages to, from and between the three internal units is in a predetermined, hierarchical direction. For example, any command message from the control unit is communicated to the accounting unit, where it is processed either for local action in the accounting unit and/or for a command message in the printing unit. On the other hand, any message from the printing unit is communicated to the accounting unit, where it is either used for internal information or merged with additional data and communicated to the control unit. And, any message from the accounting unit is initially directed to the printing unit or to the control unit.
Some commerically available postal meters which utilize the aforesaid communication system have been provided with a mechanically operable field service switch which is operable to indicate to the meter that a service mode of operation of the meter is in effect in which various messages are given an alternate interpretation, for example, commanding or requesting the postal meter to display selected values stored in the postal meter. In this connection reference is made to U.S. Pat. No. 4,280,180 for an Electronic Postage Meter Having Field Resettable Control Values, issued to A. B. Eckert et al. and assigned to the assignee of the present invention. In U.S. Pat. No. 4,280,180, a second, key controlled, three-position, mechanical switch, is also provided, to permit an authorized user to initiate a series of routines allowing the user to recharge the postal meter with a predetermined amount of additional postage.
To that end, the positions of the three position switch are identified as the "operate", "enter amount" and "enter combination"positions. By positioning the three-position switch in either the "enter combination" or "enter amount" positions the operator may enter the combination or amount respectively into the meter via the keyboard. In each instance the entry results in providing an indication on the display of the entered amount or combination, as the case may be. Leaving each position generates a message causing the displayed value to be entered into the accounting unit and blanking the display for the next entry. Return of the three-position switch to the operate position in either instance causes the accounting unit to complete the recharging routine and return the meter to normal usage with the amount added to the postage unused register. In practise, the combination for this feature is obtained by calling a Data Center having information relevant to remotely enabling the resetting of the postal meter/mailing machine for which the value is being modified, such as the Data Center of Pitney Bowes Inc. To obtain the combination the operator identifies the meter by serial number, and provides the Data Center with the code which is generated and displayed to the operator upon initially moving the key from the operate position, and also provides the value of the postage which the operator is desirous of adding to the postage unused register. Whereupon the Data Center provides the operator with a unique combination for use with the enter combination key, which combination is a random or pseudorandom number which changes with each resetting of the postage used register for security reasons.
Aside from the aforesaid usage, the three position switch is disclosed in U.S. Pat. No. 4,280,180 as being operable in combination with the service switch for changing certain other values stored in the meter, including a settable limit value, consisting of a predetermined maximum postage value which will not be printed if equaled or exceeded, a low postage warning value, consisting of a predetermined value which causes the postal meter to provide a visual indicator informing the user that the postal meter should be recharged, and a dollar unlock value, consisting of a predetermined postal value which will not be printed at any one time unless something is additionally done by the operator after the select postage key is initially actuated.
An object of the present invention is to provide a simply constructed, non-compartmentalized postal meter/mailing machine which includes a modified version of the aforesaid prior art communication system;
Another object is to provide a simply constructed non-compartmentalized, stand-alone, mailing machine which includes an electronically controlled postal meter incorporating a modified version of the aforesaid prior art communication system, and which includes improved means for servicing the mailing machine;
Another object is to provide an electronically controlled postal meter/mailing machine, having a keyboard, with means for entering and modifying various values in the same, including the serial number of the meter/machine via the keyboard; and
A further object is to provide an electronically controlled postal meter/mailing machine including a communication system having a single micro-computer which is programmed so as to retain the hierarchical communication and serial message transmission features of the aforesaid prior art communication system for implementing the control, accounting and printing functions of the postal meter/mailing machine, and which includes improved means for informing the user that the date should be checked, invoking various routines for displaying information stored in the postal meter and changing selected values stored in the postal meter.